This invention relates to a mineral mining installation for use in a steeply-inclined longwall working, and to a method of introducing a mineral mining installation into a steeply-inclined longwall working.
As is well known, the economical working of steeply-inclined coal seams gives rise to technical problems which have hitherto not been satisfactorily solved. The heavy roof support and winning installations, which have proved successful in winning mineral material in horizontal or moderately-inclined workings, cannot be successfully used in steeply-inclined workings because of the considerable forces associated with the steepness the incline. Moreover, in order to work steeply-inclined seams economically, it is essential that the roof support units can be introduced into, and removed from, the steeply-inclined working in a rapid manner, and this is not possible using the type of installation referred to above.
A known type of mineral mining installation for winning mineral material (such as coal) in a steeply-inclined working comprises a ladder-shaped support frame, a roof support assembly, and a winning machine (such as a plough) movable to and fro along the face-side of the roof support assembly. The support frame extends over the entire length of the longwall working, and is constituted by a pair of longitudinal beams (stringers) interconnected by a plurality of transverse beams (rungs). The face-side longitudinal beam forms a guide rail for a coal plough, and the goaf-side longitudinal beam supports a goaf screen. The transverse beams form part of the roof support units which constitute the roof support assembly, the transverse beams carring hydraulic props which support the roof of the working (see DE-PS No. 1 217 905). The main disadvantage of this type of installation is that it is relatively heavy and bulky. Moreover, as the face is won, the individual roof support units have to be removed from the bottom roadway and replaced at the top roadway.
Another known type of installation for use in steeply-inclined workings also has a ladder-shaped support frame. Here, the face-side longitudinal beam consists of a plurality of beam sections pivotably connected together, the face-side longitudinal beam again forming a guide rail for a winning machine (see DE-OS No. 1 608 278). The transverse beams, which interconnect the two longitudinal beams of the support frame, support and guide the roof bars and/or the floor sills of the roof support units. In this arrangement, each roof support unit is guided by transverse beams on both sides thereof. It is necessary, therefore, to provide either two or four transverse beams for each roof support unit. These transverse beams are interconnected, in pairs, by cross-pieces which support the advance mechanisms of the roof support units. Here again, this installation is relatively bulky and heavy, and considerable expenditure of time and effort is required for introducing it into a steeply-inclined longwall working.
The main object of the invention is to provide a mineral mining installation for use in a steeply-inclined longwall working which is of relatively simple construction, and which is relatively easy to introduce into, and remove from, such a working in a relatively rapid manner, so that the face of the working can be won economically. A further object of the invention is to provide an installation which utilises light-weight roof support units having only a moderate load-bearing capacity, and in which the operating forces that occur (and in particular the forces arising from the incline) are controlled in a reliable manner, so that the winning equipment associated with the installation can be readily adapted to different operating conditions. Another object of the invention is to provide a simple and economical method of introducing a mineral installation into a steeply-inclined longwall working.